Title

Authors

Date of Completion

January 1999

Keywords

Health Sciences, Nutrition|Health Sciences, Public Health

Degree

Ph.D.

Abstract

In order to better promote breastfeeding through and beyond the onset of lactogenesis stage II (OL) (i.e., the onset of copious milk secretion after delivery), it is essential to understand the factors controlling this process. Our longitudinal survey of 192 postpartum (pp) women delivering at Hartford Hospital, Hartford, Connecticut identified the following significant risk factors for delayed OL (i.e., OL ≥ 72 hours pp): White/Hispanic ethnicity, heavy/obese body build, unscheduled Cesarean delivery, vaginal delivery with prolonged stage II labor, infant birth weight < 8 pounds, and exclusive formula feeding. The breastfeeding women in this survey were followed-up to assess the duration of any breastfeeding. Multivariate survival analyses demonstrate that, among women planning to breastfeed for at least 6 months, those with an early OL breastfed longer than their counterparts with delayed OL (p < 0.00001). This relationship was not observed among women planning to breastfeed for < 6 months. ^ To determine if breast pumping impacts on the timing of OL, 60 women giving birth via Cesarean delivery at Hartford Hospital were randomly assigned to either the breast pumping group, which used a double electric breast pump for six 10–15 minute sessions between 24 and 72 hours pp, or to the control group, which held the pump to their breasts without suction for the same amount of time. At three breastfeeding sessions daily, infants were weighed before and after feeding and mothers were interviewed regarding maternal perception (MP) of OL. Breast pumping had no beneficial impact on milk transfer (MT) or NT. Among primiparous women, the pumping group tended to experience a delayed OL and shorter breastfeeding duration. ^ In order to assess the validity of MP as an indicator of OL, MP data were compared to MT data, the “gold standard” for determining OL. The sensitivity and specificity of MP as an indicator of OL were 71.4% and 79.3%, respectively. The determinants and consequences of delayed OL, as defined by either low MT or delayed NT, were similar. We conclude that MP is a useful public health marker of OL. Further studies are needed in other cultures to conclusively validate MP as an indicator of OL. ^